The present invention refers to a locking system for a cable terminal in a plug case, and in particular to a locking system including a turning tool by which locking pins of the cable terminal are deformed and forced against projections of the plug case for preventing a displacement of the cable terminal in direction of a longitudinal axis.
It is known to retain cable terminals that are securely fixed to cable ends in plug cases by elastic hooks which lock behind respectively formed parts during insertion of the cable terminals in the plug case. In order to prevent a disengagement of the cable terminal from the plug case, e.g. through repeated vibrations during operation of a motor vehicle, an additional safety mechanism is incorporated in form of locking pins which are attached to the cable terminal and twisted by a turning tool after insertion of the cable terminal in the plug case, such that the locking pins bear in form-fitting manner upon or in complementary projections. An axial displacement of the cable terminal is then effectively eliminated thereby.
The deformation of the locking pins is accomplished by a turning tool which engages the locking pins in form-fitting manner and by which the locking pins are bent when slightly turning the tool while the cable terminal remains in position. The tool is inserted into the plug case from the open end opposing the cable, and then turned. Examples for a turning tool include a sleeve slotted on one end, or a pin that is shaped on one end in form of a spade, or any other suitable design which matches the shape and configuration of the cable terminal and their locking pins.
Since turning tools of this kind are preferably incorporated in devices which simultaneously check for defective connections, as disclosed e.g. in German Patent No. DE 35 04 606, the rotation of the turning tools is suitably effected by an axial displacement of the testing unit. In order to convert the axial displacement of the testing unit into a rotational motion of the turning tool, a lateral pin is formed on the turning tool for engagement and guidance in a curved slotted guideway of a sleeve which surrounds the turning tool. A drawback of such a configuration is the spotwise support of the pin upon the side wall of the slotted guideway, because a spotwise support results in considerable wear in particular because the deformation of the locking pins requires a certain force application which unduly strains the pin and the slotted guideway and thus leads to a relatively short service life. This in turn adversely affects the production costs.